The orchid Spiranthes ovalis at Pleasant Valley Conservancy.
Spiranthes ovalis
is a relatively uncommon member of the Orchid family. In Wisconsin it is a
Special Concern species with a C value of 10.
The Wisconsin Herbarium has a few collections made some
years ago, all from Grant County, and a population was also recorded in 2013 from
Waukesha County. (See Carter and Pace paper in The Michigan Botanist, Vol. 52,
pp 105-108.) The Wisconsin Natural Heritage Inventory also shows this species
in a few other counties in southwestern Wisconsin. However, all of the sites where
this species has been observed are very small, making conservation of this
species the highest priority.
In a recent visit to PVC, Scott Weber and Muffy Barrett of
Bluestem Farm discovered S. ovalis in
our bur oak savanna.
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| Spiranthes ovalis close-up; Scott Weber photo 9-10-2016 |
This small population, 7 plants, was almost buried among
tallgrass savanna, but the tiny plants were erect and healthy.
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| Single plant (arrow) surrounded by tallgrass savanna |
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| You have to look carefully to see these tiny plants among the lush savanna understory |
Later Kathie and I
discovered another small population (4 plants), also among the bur oak savanna.
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| Spiranthes ovalis in a rocky dolomitic habitat near a remnant population of lead plant |
More sites may well be present, but because of the tall lush grass and forbs at
this time of year, it is difficult to search for such tiny plants. You have to stumble on them.
According to the Wisconsin DNR, this species is found in
“open bur oak-shagbark hickory forests on dolomite”. This is exactly the
habitat where the PVC populations were found.
We had seen Spiranthes plants a few years ago but thought they were the more common S. cernua. It took a visit from Scott Weber, an orchid expert, to recognize what we had.
